Dry cleaning compositions

ABSTRACT

Soaps for use with dry-cleaning solvents, especially carbon tetrachloride or trichlorethylene, consist of a fatty acid soap with a content of a polyglycol, and with or without a chlorinated aliphatic hydrocarbon.  For example, 14.2 gm. of caustic soda is dissolved in 25 cc. of water and stirred into 100 gm. of oleic acid in 100 cc. of trichlorethylene; 70 gm. of triethylene-glycol or 50 cc. of diethylene glycol is added; the product is dissolved in trichlorethylene for dry-cleaning.

Patented Feb. 16, 1937 UNITED STATES 2,010,908 par CLEANING ooMrosmoNsArthur Andrew Levine, Niagara Falls, N. Y., as-

signor, by mesne assignments, to E. I. du Pont de ,Nemours and Company,a corporation of Delaware No Drawing, Application September Serial No.563,671

2 Claims.

This invention relates to the art of soap making and more particularlyto the manufacture of soap for use in dry cleaning with chlorinatedhydrocarbon solvents.

Soaps for use in dry cleaning must have the ability to dissolve in thedry cleaning fluids and yet not hydrolyze or precipitate therefrom inthe presence of small amounts of water. Various dry cleaning soappreparations have been proposed which contain so-called stabilizerswhich to a greater or lesser extent inhibit precipitation ordeterioration in the presence of water. These preparations have not beensatisfactory for use with chlorinated hydrocarbon dry cleaning solventsbecause their solubility in such solvents is limited. A furtherdisadvantage is that the stabilizer has often a low boiling point andwhen the solvent is purified by distillation, the stabilizer is notseparated therefrom. When the solvent has been reused and repurified anumber of times, the quantity of stabilizer thus introduced is oftensufficient to appreciably alter the properties of the solvent.

An object of this invention is to provide a dry cleaning soappreparation which is miscible in substantially all proportions inchlorinated hydrocarbon dry cleaning solvents and which is stable in thepresence of relatively large amounts of water. A further object is toprovide a soap which does not contain relatively low boilingconstituents. A still further object is to provide a soap which exertsno solvent action upon dyes or fabrics. Other objects will appearhereinafter.

These objects are accomplished by incorporating one or more of thepolyglycols in a fatty acid soap, with or without the addition of achlorinated hydrocarbon.

According to one method of practicing my invention, I saponify a fattyacid with a caustic solution and add a chlorinated hydrocarbon, forinstance trichlorethylene, and a polyglycol, for instance diethyleneglycol or triethylene glycol. The soap so obtained has excellentdetergent properties and is soluble in all proportions in chlorinatedhydrocarbon dry cleaning solvents.

The following examples serve to show some methods of practicing myinvention.

Example 1 14.2 g. of NaOH was dissolved in 25 cc. of water and theresulting caustic solution was added with vigorous stirring to a mixtureof 100 g. of oleic acid and 100 cc. of trichlorethylene. To theresultant paste, '70 g. of triethylene glycol was added, forming aperfectly clear solution. This soap was completely soluble intrichlorethylene and had excellent detergent properties. There was nosign of precipitation when up to 5 cc. of water was added to 100 cc. ofthe liquid soap.

Example 2 14.2 g. of NaOH was dissolved in 25 cc. of water and addeddrop by drop to a mixture of 100 g. of oleic acid and 100 cc.- oftrichlorethylene. To the resulting paste, .50 .cc. of diethylene glycolwas added, giving a perfectly clear solution, soluble intrichlorethylene in all dilutions.

Example 3 14.2 g. of NaOH were dissolved in 25 cc. of water and addeddrop by drop to a mixture of 100 g. oleic acid and 100 cc. of carbontetrachloride. To the resulting paste, cc. of triethylene glycol wasadded, giving a perfectly clear solution of this soap, soluble in carbontetrachloride in all dilutions.

Although the examples cited show soaps prepared by saponification of afatty acid in the presence of chlorinated hydrocarbon, I may preparesoap by any of the well known methods and then dissolve this soap inchlorinated hydrocarbon and polyglycol or mix it with polyglycol alone.

Although I prefer to add suflicient chlorinated hydrocarbon to the soapto form a solution, my

invention is not limited to the preparation of a liquid soap but mayinclude other forms such as jellies and pastes. For instance I mayprepare a paste by mixing soap with polyglycol alone. Such paste iscompletely soluble in chlorinated hydrocarbon dry cleaning solvents, forinstance trichlorethylene or carbon tetrachloride.

In dry cleaning with my soap preparation, it is preferable to use a soapcontaining as one constituent the same solvent that is used as drycleaning agent; but this is not essential. For instance, a soap madeaccording to my invention and containing trichlorethylene may be used indry cleaning operations employing either trichlorethylene or carbontetrachloride as solvent.

Relatively large quantities of water may be added to solutions of mypolyglycol soaps in dry cleaning solvents without causing precipitation.For instance I found that no sign of precipitation or cloudinessoccurred when 4.5 cubic centimeters of water were added to 1 liter of a1% trichlorethylene solution of a soap made as herein described andcontaining diethylene glycol. This toleration of relatively largeamounts of water makes possible excellent dry cleaning without thespecial precautions to exclude moisture heretofore necessary in cleaningwith mixtures of chlorinated hydrocarbon solvents and soaps.

In the distillation of a solvent which has been used in a dry cleaningoperation, it is desirable that the distilled solvent be notcontaminated by material derived from the dry cleaning soap. Althoughthe amount of such material introduced may be relatively small duringeach operation, after repeated dry cleaning and distillation operationsthe amount becomes significant. The solvent properties of the drycleaning solvent likewise become altered after several recoveries whensoap having volatile constituents is used. When polyglycols are used asstabilizers in dry cleaning soaps, substantially no such contaminationof the dry cleaning solvent results, because the high boiling points ofthese stabilizers prevent them from distilling with the solvent.

The polyglycols have substantially no solvent action on celluloseacetate under the conditions normally existing in dry cleaningprocesses; and soaps made according to my invention may be used for drycleaning cellulose acetate fabrics without danger of harming the goods.

The advantages of my soap may be summarized as follows:

1. Complete solubility in chlorinated hydrocarbon solvents.

2. May be made either as a jelly or as a liquid.

3. Relatively inexpensive.

4. The boiling point of the stabilizer is high,

which prevents it being distilled over with dry cleaning solvent.

5. A relatively large amount of water may be present during cleaningoperations without causing precipitation or interfering with thedetergent action of the soap.

6. Substantially no solvent efiect upon dyes or fabrics.

By the term polyglycol in the specification and claims, I meandiethylene glycol or the product obtained by the condensation of thismaterial with one or more molecules of ethylene glycol (CH2OH-CH2OH).

I claim:

1. An odorless dry cleaning composition consisting of trichlorethylenewhich contains in solution about 1% of a soap composition consistingsubstantially of 108 parts of an oleic acidsodium soap, 147 parts oftrichlorethylene and 70 parts of triethylene glycol, said proportionsbeing by weight.

2. An odorless dry cleaning composition consisting of trichlorethylenewhich contains in solution about 1% of a soap composition consistingsustantially of 108 parts of an oleic acid-sodium soap, 147 parts oftrichlorethylene and 56 parts of diethylene glycol, said proportionsbeing by weight.

ARTHUR ANDREW LEVINE.

